Swimming is good for your bones

Swimming is good for your bones

Getting enough exercise is crucial on your cancer journey. If you have or have had breast cancer, it’s particularly important because the side effects of treatment put you at a higher risk of getting osteoporosis.

Because you’re supported in the water when you swim, it isn’t considered to be weight-bearing exercise, so it’s assumed that swimming isn’t good for building bone strength. It’s true that swimming isn’t as effective as weight-bearing exercise at building bone density. But increasing bone density isn’t the only effective way to strengthen your bones.

Bone isn’t dead tissue at all. It’s constantly being broken down and replaced in a system called bone remodelling. Doctors are keen for patients at risk of osteoporosis to take drugs which build up bone density. They work by preventing the breakdown of old bone. The trouble is that the old bone is poor quality and, although preserving it does increase bone mass, the bone becomes poor quality and ends up looking like Swiss cheese. This makes it quite brittle.

Brittle bones fracture more easily, and there’s evidence that some people experience unusual fractures after taking bisphosphonates (1). There are many other side effects of taking these drugs, including upper digestive system problems, severe musculoskeletal pain, increased risk of oesophageal cancer, and osteonecrosis of the jaw (1). But the fact that they can increase fracture risk means that bone density isn’t the only way to improve your bone strength. The quality of the bone is even more important. And that’s where exercise comes in (2).

Weight-bearing exercise works because stressing the bone forces it to produce new bone cells. Swimming can’t do that because you don’t have the benefit of gravity. But it is good for building up muscle, and more muscle also stresses the bones. So, although swimmers’ bone density won’t be as high as people who practise other sports, they have an increased rate of bone turnover. This means that the rate of breaking down old bone and replacing it with new bone is increased, and this results in the quality of the bone improving (3).

Many breast cancer patients end up with lymphoedema if they have lymph nodes removed. Lymphoedema happens because, without the lymph nodes, circulation of lymph is more difficult and the fluid builds up, usually in the arms. Certain types of exercise can help you manage the symptoms of lymphoedema by improving the circulation of lymph, with swimming and pool exercises being some of them (4). Swimming is gentle exercise because of the support in the water, and can also promote feelings of well-being. But the resistance of the water can still help to build up muscle and improve the health of your heart and lungs. For ideas on the best kind of exercises to do in the pool and advice on staying safe whilst exercising, this site is very helpful - http://www.lymphnotes.com/article.php/id/24/.

If you do choose to add swimming to your exercise regime, swimming in the ocean is preferable to a pool, to avoid the toxins that can be created in a pool, as you will know if you’ve read my book. And if you’re swimming outdoors don’t forget to use sunscreen to avoid getting burnt. Just remember that oxybenzone, commonly used in sunscreens, is toxic. Sunscreens containing zinc oxide or titanium oxide are more effective and much safer for you.

Remember, no matter how slowly you go, you’re still lapping everybody on the couch!

References

1.   Kennel K, Drake M. Adverse Effects of Bisphosphonates: Implications for Osteoporosis Management. Mayo Clin Proc. 2009;84(7):632-638. doi:10.1016/s0025-6196(11)60752-0

2.   Fonseca H, Moreira-Gonçalves D, Coriolano H, Duarte J. Bone Quality: The Determinants of Bone Strength and Fragility. Sports Medicine. 2013;44(1):37-53. doi:10.1007/s40279-013-0100-7

3.   Gómez-Bruton A, Gónzalez-Agüero A, Gómez-Cabello A, Casajús J, Vicente-Rodríguez G. Is Bone Tissue Really Affected by Swimming? A Systematic Review. PLoS One. 2013;8(8):e70119. doi:10.1371/journal.pone.0070119

4.   Lymph Notes. Water Exercises for Lymphedema. Lymphnotes.com. http://www.lymphnotes.com/article.php/id/24/. Published 2022. Accessed June 28, 2022.